Self-contained heating means for cans and the like



NOV. 12 1935 .v EGGERT r- 2,020,292

SELF CONT AINED HEATING MbANS FOR CANS AND THE LIKE Filed Sept.-17, 1934 5 Fig.4

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Patented Nov. 12, 1935 SELF-CONTAINED HEATmG MEANS FOR CANS AND THE LIKE Felix Eggert and Eugen Helff, Graz, Austria Application September 1'7, 1934, Serial No. 744,284

In Austria October 5, 1932 14 Claims.

We have filed applications in Austria on the th October 1932 and on the 28th July 1933, and in Germany on the th March 1934.

This invention relates to preserving cans of the 5 type equipped with self-contained heating means for heating the contents before use. Cans of this nature are already known, which are double walled at the bottom for the reception of a glowing. combustion cartridge of a nature to burn 0. without any additional air supply, and in which the inner wall of the double bottom is provided with a depression into which the cartridge projects with considerable clearance, that is to say with the interposition of an air cushion between 5 the cartridge and the wall of the depression. This air cushion tends to check the transmission of heat to the contents of the can, and at the same time constitutes a danger to the sheet metal covering of the cartridge which is apt to become 10 burnt up in the presence of this air and thus to expose the wall of the can to excessive heat. The present invention provides an improved type of can with self-contained heating means,

and has for its object to obviate the above-men- 55 tioned drawbacks, and to provide heating means which will function safely and reliably under all conditions, and which will retain and continue to impart heat to the contents of the can for a considerable length of time after the actual 50 process of combustion has ceased.

A further object of the invention is to provide simple and eflicient means for igniting the charge of glowing combustion composition, and reliable means for preventing unintentional ignition thereof through inadvertenceor any other cause.

.A further object of the invention is to-provide heating means in which the igniting device is in the form of a unit capable of being detached from the glowing charge container or cartridge and fitted to a refill to form an independent heating unit for insertion into a can having a suitably recessed end.

With these'and other'objects in view, the invention consists in inserting into a hollow cupshaped recess in one end of the can, a closely fitting thick-walled potv made of refractory mate-' rial and containing a charge of a glowing combustion composition. Adjoining the open end of this pot there is a perforated cylindrical member enclosing the igniting iievice and enclosing this latter and the cylindrical member thereis preferably provided an outer sheathing which may conveniently serve to assemble the parts of the complete heating device, and which may also be extended to cover the entire pot. The fact that the thick-walled pot is directly inserted with a close fitv into a recess in one end of the can provides very favorable conditions of heat transmission ,with practically no loss of heat, while at the same time the use of refractory material 5 for the wall of the pot precludes any risk of excessive heat or damage to the w all of the can, ensures steady: heat transmission to the contents of the can, and conserves heat which is gradually imparted to the can during a considerable length 10 of time after the actual process of combustion has ceased. The cylindrical member adjoining the open end of the potserves to insulate the lattermore particularly from the portion of the end of the can between the re-entrant portion 15 forming the recess and the outside edge, so'that it is unnecessary to stand the can on a fireproof baseduring the operation of the heating means. The igniting means consist essentially of a striking pin provided with a match head gripped between suitable friction surfaces, so that when the pin is thrust forward the match head passing between the friction surfaces is caused to ignite. A suitable rapid igniting composition can be provided on or embedded in the glowing 5 combustion charge opposite the match head, to ensure reliable and rapid ignition of the latter by the burning match head. The essential parts of the igniting device are mounted in a closure element associated with the above-mentioned cy- 3o lindrical insulating member, and means for operating or releasing this device can be provided in conjunction with hood-shaped portion of the sheathing covering the rear end of the complete heating .unit. 35 In accordance with the invention, the heating unit is so constructed that it can be stored and shipped independently of the cans, and inserted or replaced as required, in suitably constructed cans. The unit thus provided can be arranged so to be held in position in the recess formed by a re-entrant portion of the end wall of the can,

7 by virtue of fitting closely in this recess, The

invention also provides, as above mentioned, for the igniting device and the cylindrical insulating 4,5

. member to be so assembled in the hood-shaped portion of the outer sheathing or shell that they constitute an independent unit which is detachably fitted to the pot containing the glowing charge, so that it can be removed after the charge 5 is spent and replaced on a refill pot for insertion in a fresh can.

We have also found that the sheathing of the pot can be dispensed with, more particularly when the igniting device is arranged to be de- 55 tachable and capable oi. being used repeatedly in connection with refill pots, in which case the igniting unit can be provided with a protecting hood, and arranged to fit tightly on the end oi. the pot, to form a cartridge-like unit for insertion in the cup-shaped recess provided in one end or the other of the can.

Forms of construction embodying the invention are shown, by way of example, in the accompanying drawing, in which:

Fig. 1 shows, in longitudinal section, one form of the invention.

Fig. 2 shows a modified i'orm, likewise in longitudinal section.

Fig. 3 is a detail view of the form 01' construction shown in Fig. 2, on a reduced scale, showing the igniting device in the released position.

Fig. 4 shows a further modification, in longitudinal section.

Fig. 5 is an enlarged cross sectional view taken on line 5-5 of Fig. 4

Referring to Fig. 1, I denotes the can one end wall 2 of which is provided with a re-entrant portion forming a cup-shaped recess 3 for the accommodation of the heating cartridge. This latter consists essentially of a sheet metal shell B, a lining 5 of refractory material (ma'gnesite, soapstone, or the like), and a charge 6 of glowing combustion composition. The outer shell is completed by the hood-shaped portion 8 provided with apertures 1. Inside this hood-shaped portion 8 of the shell, and pressed by it against the end of the refractory lining or pot 6 there is provided a cylindrical member 9 (likewise of magnesite, soapstone, or the like) having a fiange portion adjacent the pot with interruptio s or apertures it? which are covered over on the inside by a network, gauze, or the like M. This cylindrical member 9 has a central hole lined by a bushing 52 in which the stg pin it is guided. The match head on this pin is situated.

between the two inteiiorly roughened spring tongues i2 pertaining to the bushing 82. When the striking pin is thrust forward the match head rubs against the roughened tongues and ignites, and then strikes in the burning state.

against the igniting composition i l embedded in the top of the charge oi. glowing combustion 6, with the result that the latter becomes ignited. The gases generated by combustion can emape through the apertures it and i.

In order to protect the contents of the heating cartridge from the eflfects ot the atmosphere during storage, the apertures l and the opening i5 in the hood giving access to the end of the striking pin can be sealed with strips oi paper or the like.

As shown in Fig. 2, the heating, cartridge according to the present invention can also be used with ordinary cans when these latter are provided with a screwed on lid. In this case it is merely necessary to use a special lid 2 having 9. suitable recess 3 for the accommodation of the heating cartridge, and to substitute this lid i'o'r the ordinary lid on the can, after which the heating device can be used in the same way as with a specially constructed can, already equipped with the heating device.

The heating cartridge shown in Fig. 2 is substantially the same as that shown in Fig. 1, the only difference being that the cylindrical member is in the form of a sheet metal stamping 3', and the striking pin provided with spring operation and hand operated releasing means.

For this purpose there is, provided within the hood-shaped portion of the shella disc 20 stressed by a spring 2| and provided with an aperture through which a retaining and releasing member 23, supported against the hood, is adapted to pass. This member 23 is in the form of a pin having a head seated in a depression in the hood and a cross piece on its outer end and adapted to pass through a slot aperture in the disc 20, and when turned after being passed through the slot aperture, to retain this disc in the raised 'position against the action of the spring 2| over the end or the striking pin l3. Whenthe pin 23 is twisted from the position shown in- Fig. 2 to that shown in Fig. 3, the cross piece 22 is brought into registration with 1 the slot aperture in the disc 20 and the latter is thereby liberated and actuates the striking pin l3 under the action of the spring 26. The retaining and releasing means employed could be of any other suitable construction, provided they 2 be operable from the outside to released actuating means for the striking pin. The end of the pin 23 could for instance be screw threaded in the disc 23 so that several turns 01' the pin would be required to operate the igniting device. 2 In the example shown, the head of the pin 23 is provided with a slot for engagement by a small coin or any other suitable implement.

In the form of construction shown in Fig. 4, one end 3| of the cam I is provided with a 3 re-entrant portion 32 which forms a recess which is preferably widened somewhat towards the mouth, as shown at 33. The heating cartridge capable of being inserted into and taken out of this recess consists of the thick-walled refrac- 3 tory pct 34 and of'a detachable head portion frictionally fitted to the open end of the pot. This portion comprises a cap 36 having a shouldered and flanged lower edge 36 with which it is tightly fitted to the top of the pot, 4' as shown. This cap 36 is provided with apertures 81 which are preferably covered over by a network or gauze 38. Riveted or otherwise fastened to the cap 36 there is a second cap 36 adapted to serve as a protectlnghood and 4,5 m means for grasping and holding the car-. tridge in the hand. Between the two caps 36 and 35 there is provided an insulation layer 39, for example of asbestos sheet or the like. To one or both of these caps there is attached 5 a spring 50 of lyre-shaped cross-section, or otherwise suitably shaped, which serves as a guide for the striking pin M, and which together with this latter constitutes the igniting device for the charge 42 of glowing combustion com- 55 position. A match head on the lower end of the pin 4| contacts with the roughened surface on the inside of the spring 40 and rubs against the same, when the pin is thrust forward, thus causing the ignition oi the charge 42. 0

The essential feature 91! the form of construction last described is the fact that the pot is readily detachable from the head portion comprising the igniting device, so that these parts can be repeatedly re-used. Further, the thick- 5 walled pot has no sheathing or shell made of sheet metal, and is adapted to be directly inserted into the cup-shaped recess in the end wall of the can.

The heating device provided by the inven- 70 tion can be used in conjunction with any type of can or the like container, and' also for example with provenderor mess-tins, provided, they be suitably shaped. The device ,is thus particularly convenient Ioruse by hikers, mountaineers, and explorers, since it does away with .the necessity for carrying cookingequipment.

Mess-tins intended for use with the heating cartridges according to the present invention can be provided with a suitable safety valve, for example of' the spring type.

We claim: i

1. In a can intended for the reception of stuff or the like, an end wall having a re-entrant portion forming a cup-shaped recess, a relatively thick-walled pot of refractory material adapted to fit closely in the said recess, a charge of glowing combustion composition in the said pot, a perforated cylindrical member adjoining the open end of the said pot, and means housed within the said member for igniting the said charge.

2. In a can or receptacle for the reception of foodstuff or the like, an end wall having a re-entrant portion forming a cup-shaped recess, a relatively thick-walled pot of refractory 7 material adapted to fit closely in the said recess, a charge of glowing combustion composition in the said pot, .a' perforated cylindrical member adjoining the open end of the said pot towards the outside of the receptacle, a holder attached to the said member, friction surfaces associated with the said holder, a striking pin .slidable in the said holder, and a match head adapted to engage between and to be ignited by the said friction surfaces.

3. In a can intended for the reception of foodstufi or the like, an end wall having a re-entrant portion forming a cup-shaped recess, a, relatively thick-walled pot of refractory material fittedclosely in the said recess, a charge of glowing combustion material in the said pot, a perforated cylindrical member adjoining the open end of the said pot towards the outside of the can,

a covering of network material over the inside of the said member against the perforations therein, and means housed within the said member for igniting the said charge. a

- 4, In a can or receptacle for foodstuff and the like, an end wall having a re-entrant portion forming a cup-shaped recess, a relatively thickwalled pot of refractory material closely fitted in the said recess, a charge of glowing combustion composition in the said pot, a perforated cylindrical member adjoining the open end of the said pot towards the outside, a perforated hood attached to the said pot and adapted to enclose the said member and to press the same :against the end of the pot, and means housed within the said hood for igniting the said charge. 5. In a receptacle for foodstuff and the like, jan-end wall having a re-entrant portion forming a cup-shaped recess, a relatively thick-walled pot of refractory material closely fitted in the said recess, a charge of glowing combustion composition in thesaid pot, a supply of rapidly igniting composition on the outer end of the said charge, a perforated cylindrical member adjoining the outer end of the said-pot, and means associated with the said member for igniting the said charge.

6. In a receptacle for foodstuff and the like, an end wall having a re-entrant portion forming a cup-shaped recess, a relatively thick-walled pot of refractory material adapted to fit into the said recess, a metal shell encasing the said pot, a charge of glowing combustion composition in the said pot, a perforated cylindrical member adjoining the outer end of the said pot, a perforated hood attached to the said shell and adapted to enclose the said member and to press the same against the outer end of the said pot, and means housed within the said hood and associated with the said member, for igniting the said charge. 5

'7. In a receptacle for foodstuff and the like,

an 'end wall having a re-entrant portion forming a cup-shaped recess, a relatively thick-walled pot p: refractory material adapted to fit into the said recess, a metal shell encasing the said pot, a charge of glowing combustion composition in the said pot, a cylindrical member of refractory material-having a centrally pierced solid outer portion and'a perforated flange portion adjoining the outer eirdpf the said pot, a covering of network material ornthe inside of the said flange portion against the said apertures therein, a perforated hood attachedito the said. shell and adapted to enclose the said member and to press the same against the outer end of the said 20 pot, a lining in the central hole in the saidSolid portion, interiorly roughened spring tongues on the said lining, a. striking pin slidable in the said lining and having its outer end normally projecting through a countersunk opening in the 25 .said head, and a match head on the other end of the said pin normally situated immediately above the said'tongues.

8. In a receptacle for foodstufi and the like,' an end wall having a re-entrant portion forming 30 a cup-shaped recess, a relatively thick-walled pot of refractory material adapted to fit into the said recess, a metal shell encasing the saidpot,

a charge of glowing combustion composition in the said pot, a perforated cylindrical member 35 adjoining the outer end of the said pot, a perforated hood attached to the said shell and adapted to enclose the said member and to press the same against the outer end of the said pot, selfacting means housed in the said hood for igniting the said charge, and means operable by hand from the outside for initiating the functioning of the said self-acting igniting means.

9. In a receptacle for foodstuff and the like, an end wall having a re-entrant portion forming a cup-shaped recess, a relatively thick-walled pot of refractory material adapted to fit into the said recess, a metal shell encasing the said pot, a charge of glowing combustion composition in the said pot, a perforated cylindrical member adjoining the outer end of the said pot, a concave head on the said'cylindrical member, a perforated hood attached to the said shell and adapted to enclose the said member and to press the same against the outer end of the said pot, a holder sleeve-attached to the said head, interiorly roughened spring tongues on the end of the said sleeve neare:t the said charge, a striking pin slidable in the said sleeve, a match head on the end of the said pin normally situated immediately 60 above the said tongues, a disc above the other end of the said pin, an expanding spring tensioned between the said disc and the said hood, and means operable from the outside for retaining the said disc raised against the action of 5 thesaid spring and for releasing the same to strike against the said pin under the action of the said spring. V

10. In a receptacle for foodstuff and the like,

aheating device as claimed in claim 9 in which 7 retaining and releasing means comthe said prise a pin detachably connected to the said disc and supported by the said hood.

the said retaining and releasing means comprise a slotted aperture in the said disc, a pin having a slotted head countersunk in a depression in the said hood and at the other end a cross piece adapted to register with and to pass through the said slottedaperture, and on being turned out of registration with the said aperture after having been passed therethrough, to retain the said disc in the raised position against the action of the said spring. i

12. A heating unit for insertion in a recess in an end wall of a receptacle for foodstuff and the comprising a relatively thick-walled pot of refractory material,- a charge of a glowing combustion composition in the said pot, a perforated, cylindrical, cap-shaped member frictionally fitted to the outer open end of the said pot, network I material onthe inside of the said member against the apertures therein, and means within the said member for igniting the said charge.

13. A heating unit for insertion in a recess in an end wall of a receptacle for foodstufi and the like, comprising a relatively thick-walled pot of refractory material, a charge of a glowing comhustion composition in the said pot, a perforated,

cylindrical, cap-shaped member frictionally fitted to the open end of the said pot, network material on the inside of the said member against the perforations therein, an outer protecting cap attached to the head of the said member, a layer of insulating material between the head of the said member and the head of the said protecting cap, and means within the said member for igniting the said charge.

her, a layer of insulating material between the head of the said member and the head of the said protecting cap, a spring of lyre-shaped cross section attached to and dependent from the head of the said member, at least one roughened surface on the inside of the said spring, an ignition pin held in and guided by the said spring and having its outer end projecting through an aperture in the said heads, and a match head on the other end of the said pin adapted when the said pin is thrust forward to rub against the said surface and thereby to ignite.

FELIX EGGERT.

EUGEN HELFF. 

